JP2009210622A - Vibration correcting device, lens barrel, and camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration correcting device etc., for suppressing occurrence of an impact or the like. <P>SOLUTION: The vibration correcting device includes: a moving means 24 for moving an optical component 16 disposed on the optical axis of an optical system in a direction crossing the optical axis; and a speed control unit 44 that changes the moving speed of the optical component by the moving means in accordance with the position and the moving direction of the optical component. The speed control unit 44 controls variation of the moving speed of the optical component 16 to be different between a case where the moving direction of the optical component 16 is close to the moving limit position P<SB>L'</SB>or -P<SB>L</SB>on control and a case where the moving direction of the optical component 16 is away from the moving limit position P<SB>L'</SB>or -P<SB>L</SB>on control. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a shake correction device, a lens barrel including a shake correction device, and a camera.

  In order to prevent an image blur due to camera shake or the like, an image blur correction apparatus of an optical component moving type that moves a blur correction optical component such as a lens is provided as one of image blur correction apparatuses provided in a camera or the like.

  As such an optical component movement type image blur correction device, an apparatus having a function of preventing the shake correction optical component from moving beyond the limit of the movable range is known. For example, a technique is known that restricts the movement of the shake correction optical component when the shake correction optical component moves within a predetermined range near the limit of the movable range of the movable optical component (see Patent Document 1).

However, in the related art, the speed of the shake correction optical component may change rapidly both when the shake correction optical component enters the predetermined range and when the shake correction optical component exits the predetermined range. A rapid change in the speed of the shake correction optical component may cause an impact or a driving sound larger than normal to an optical device on which the shake correction optical component is mounted. However, in order to improve the operational feeling of the optical device, it has been required to reduce the number of occurrences of such impacts or driving sounds.
Japanese Patent Laid-Open No. 9-80506

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a shake correction device that suppresses the occurrence of an impact or the like, a lens barrel including the shake correction device, and a camera.

In order to solve the above-described problem, a shake correction apparatus according to the present invention includes:
Moving means (24) for moving the optical component (16) provided on the optical axis of the optical system in a direction intersecting the optical axis;
A speed control unit (44) for changing the moving speed of the optical component by the moving means according to the position and moving direction of the optical component (16);
The speed control unit (44) includes a case where the movement direction of the optical component (16) is a direction approaching a movement limit position (P _L , -P _L ) on control, and a movement limit position ( The amount of change in the moving speed of the optical component (16) is changed depending on the direction away from P _L , -P _L ).

Further, for example, the speed control unit (44), the moving direction of the optical component (16), movement limit position (P _L, -P _L) on the control by the variation in the case of a direction approaching the The moving speed of the optical component (16) may be suppressed.

Further, for example, when the movement direction of the optical component (16) is a direction away from the control movement limit position (P _L , −P _L ), the amount of change is as follows: The amount of change may be smaller than the amount of change in the direction approaching the movement limit position (P _L , −P _L ) on the control.

  In addition, for example, the speed control unit (44) is configured such that the moving direction of the optical component (16) is a direction away from the center position of the moving range of the optical component (16), and the moving range of the optical component. The amount of change in the moving speed of the optical component may be changed depending on the direction approaching the center position.

Further, for example, stabilizing device according to the present invention, the center position of the moving range of the optical component (16), the movement limit position (P _L, -P _L) on the control between the switching position (P _S , -P _S )
The speed control unit (44) is arranged such that the position of the optical component (16) is closer to the control limit position (P _L , -P _L ) than the switching position (P _S , -P _S ). and some cases, the switching position (P _S, -P _S) in the case where a position close to the center position than, be characterized in that the can change the amount of change in the moving speed of the optical component (16) Good.

Further, for example, the shake correction apparatus according to the present invention is arranged in a direction further away from the control movement limit position (P _L , −P _L ) with respect to the center position of the movement range of the optical component (16). There may be a movement limit position on the dimension where the optical component (16) contacts other components.

Further, for example, the speed control unit (44) calculates the moving speed of the optical component (16) necessary for canceling the shake of the optical system, and according to the position and moving direction of the optical component, The calculated moving speed may be changed.

  A lens barrel (4) according to the present invention includes any of the shake correction apparatuses described above.

  A camera according to the present invention includes any of the shake correction apparatuses described above.

  In the above description, in order to explain the present invention in an easy-to-understand manner, the description is made in association with the reference numerals of the drawings showing the embodiments. However, the present invention is not limited to this. The configuration of the embodiment described later may be improved as appropriate, or at least a part of the configuration may be replaced with another component. Further, the configuration requirements that are not particularly limited with respect to the arrangement are not limited to the arrangement disclosed in the embodiment, and can be arranged at a position where the function can be achieved.

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
FIG. 1 is a block diagram for explaining shake correction control in a camera equipped with a shake correction apparatus according to an embodiment of the present invention.
FIG. 2 is a flowchart showing a series of processing performed by the position bias control unit shown in FIG.
FIG. 3 is a schematic diagram showing a control movement limit position and a switching position in the shake correction optical system shown in FIG.
FIG. 4 is a block diagram showing processing in the integral calculation unit shown in FIG.
FIG. 5 is a graph showing the time change of the output in the integral calculation unit shown in FIG.
FIG. 6 is a block diagram showing processing in the controller shown in FIG.
FIG. 7 is a graph showing the result of shake correction processing by the camera shown in FIG.
FIG. 8 is a flowchart showing a control flow of the position bias control unit in the shake correction apparatus according to the comparative example;
FIG. 9 is a graph showing temporal changes in position and drive amount of the shake correction optical system in the shake correction correction apparatus according to the comparative example.
Embodiment

  FIG. 1 is a block diagram for explaining shake correction control of a camera equipped with a shake correction apparatus according to an embodiment of the present invention. In the upper part of FIG. 1, a schematic sectional view of the camera is shown. The lens barrel 4 according to an embodiment of the present invention is attached to the barrel 5 of the lens barrel 4 and the housing 2 of the camera body 1 via a lens holding frame (not shown). The first optical system 10, the second optical system 12, the shake correction optical system 16, and the third optical system 14 are provided in the cylindrical body 5 of the lens barrel 4 from the incident light incident side. The second optical system 12 and the third optical system 14 are disposed along the optical axis L.

  The first to third optical systems 10 to 14 and the shake correction optical system 16 constitute a photographing optical system of the camera. At the time of photographing, subject light incident from the first optical system 10 side is transmitted to the camera body 1. Guide to the recording medium 17 provided inside the housing 2. The first optical system 10, the second optical system 12, and the third optical system 14 are attached to the cylinder 5 via first to third optical system holding frames 19, 20, and 21, respectively.

  The shake correction optical system 16 is held by a correction optical system holding frame 18. Further, the correction optical system holding frame 18 is movably attached to the cylindrical body 5 via a shake correction drive unit 24. The shake correction drive unit 24 is not particularly limited as long as the correction optical system holding frame 18 and the shake correction optical system 16 are moved substantially perpendicular to the optical axis L.

  In the present embodiment, as the shake correction drive unit 24, a voice coil motor configured by a coil provided in the correction optical system holding frame 18, a magnet that generates a magnetic field around the coil, a yoke, and the like is used. The shake correction drive unit 24 of the present embodiment includes two voice coil motors that move the correction optical system holding frame 18 in directions orthogonal to each other, and the correction optical system holding frame 18 is an arbitrary perpendicular to the optical axis L. Move in the direction of. A correction optical system position detection unit 26 for detecting the position of the shake correction optical system 16 is provided in the cylindrical body 5 in association with the correction optical system holding frame 18.

  Further, the lens barrel 4 has an angular velocity sensor 28 constituted by a gyro sensor or the like. The shake correction drive unit 24 drives the correction optical system holding frame 18 based on the detection signal detected by the angular velocity sensor 28 provided in the lens barrel 4 and corrects image blur caused by camera shake or the like.

  The lens barrel 4 includes a lens CPU 30 that controls driving of the shake correction driving unit 24. As will be described in detail later, the lens CPU 30 controls the movement of the shake correction optical system 16 via the shake correction drive unit 24 based on information about the shake of the photographing optical system obtained from the angular velocity sensor 28, and the like. Cancels the shake of the photographic optical system with respect to the subject.

  The lens CPU 30 is provided in the lens barrel 4. The lens barrel 4 can be attached to and detached from the camera body 2 via a mount (not shown). A contact (lens contact) 52 for electrical connection to the camera body 2 side is provided on the mount portion of the lens barrel 4. The lens CPU 30 is electrically connected to a body CPU 54 provided in the camera body 2 via a lens contact 52. In FIG. 1, a low-pass filter 32, a PWM driver 50, a lens CPU 30, and a lens contact 52 are provided in the lens barrel 4, and a body CPU 54 and a release switch 56 are provided in the camera body 1. The body CPU 54 is a central processing unit that controls the entire camera. In response to the signal from the release switch 56, the body CPU 54 starts or ends the restriction on the movement of the shake correction optical system 16 by the lens CPU 30.

  In FIG. 1, the processing content related to shake correction control among the arithmetic processing performed by the lens CPU 30 is shown as each processing unit (block). That is, the lens CPU 30 includes a digital low-pass filter (digital LFP) 34, a lens target speed conversion unit 42, a position bias control unit 44, an integration calculation unit 46, and a controller 48.

  The digital LFP 34 obtains a reference value for the sensor angular velocity ω detected by the angular velocity sensor 28. The lens target speed conversion unit 42 calculates the speed of the shake correction optical system 16 necessary for canceling the shake of the imaging optical system detected by the angular speed sensor 28, and uses the speed as the target speed VC1 of the shake correction optical system 16. Output. The position bias control unit 44 changes the target speed VC1 of the shake correction optical system 16 to the correction speed VC according to the position and movement direction of the shake correction optical system 16. The integration calculation unit 46 calculates a position to move the shake correction optical system 16 and outputs it as a correction lens target position Lc. Further, the controller 48 calculates a drive amount for performing PID control of the shake correction optical system 16 based on the correction lens target position Lc and the correction optical system position Lr.

  The lens CPU 30 further includes a focal length calculation unit 36, a subject distance calculation unit 38, and an EEPROM reading unit 40. These output signals related to information necessary for shake correction control to the lens target speed conversion unit 42. Hereinafter, shake correction control by the lens CPU 30 of the present embodiment will be described.

  The angular velocity information detected by the angular velocity sensor 28 provided in the lens barrel 4 is output as the sensor angular velocity ω. The sensor angular velocity ω is input to the lens CPU 30 after the high-frequency noise is removed by the low-pass filter 32. When the sensor angular velocity ω is input to the lens CPU 30, the sensor angular velocity ω is A / D converted (analog-digital converted) to become a digital angular velocity ω 1.

  Next, the digital angular velocity ω1 is input to the digital LFP 34. The digital LFP 34 calculates and obtains the reference zero angular velocity ω2, and then subtracts the reference zero angular velocity ω2 from the digital angular velocity ω1 to determine the standard angular velocity with the reference position determined. ωs is calculated.

  In the lens target speed conversion unit 42, the standard angular velocity input based on the focal length information from the focal length calculation unit 36, the subject distance information from the subject distance calculation unit 38, the lens specific information from the EEPROM reading unit 40, and the like. ωs is converted into the target speed VC1 of the shake correction optical system 16. The target speed VC1 is a speed given to the shake correction optical system 16 in order to cancel the image shake caused by the shake of the photographing optical system. The shake correction optical system 16 moves in the direction and speed defined by the target speed VC1, thereby displacing the image formation position within the image formation plane and cancels image blur caused by the shake of the imaging optical system. The focal length calculation unit 36 and the subject distance calculation unit 38 calculate the focal length and the subject distance based on detection signals from a photographing optical system position detection unit and a subject distance detection unit (not shown).

  The position bias controller 44 changes the input target speed VC1 to the correction speed VC based on the correction optical system position Lr. The correction optical system position Lr is A / D converted when a signal representing the position of the shake correction optical system 16 detected by the correction optical system position detection unit 26 is input to the lens CPU 30.

  FIG. 2 is a flowchart showing a series of processes performed by the position bias control unit 44. In the flowchart shown in FIG. 2 and the graph shown in FIG. 7, in order to simplify the processing, the shake correction optical system 16 has the center position of the movement range of the shake correction optical system 16 as the origin and is orthogonal to the optical axis L. The description will be made on the assumption that the object moves on a one-dimensional coordinate. In this case, the correction optical system position Lr means the position of the central axis of the shake correction optical system 16 on the one-dimensional coordinate. In the present embodiment, the center position of the movement range of the shake correction optical system 16 and the optical axis L substantially coincide.

As shown in FIG. 3, the center axis of the shake correction optical system 16 moves between a control movement limit position (soft limit) P _L in the positive direction and a soft limit −P _{L in the} negative direction. Be controlled. Between each soft limit P _L , -P _L and the origin, the switching position P is located at a position where the distance from the origin is 0.8 times the distance from the origin to each soft limit P _L , -P _{L. S} and -P _S are provided.

In step S001 shown in FIG. 2, the position of the shake correction optical system 16 shown in FIG. 1 is determined by determining whether or not the absolute value | Lr | of the correction optical system position Lr is smaller than a predetermined threshold value. To do. As shown in FIG. 2, in the present embodiment, the absolute value of the correction optical system position Lr | Lr | determines whether or less or not than 0.8 times the soft limit P _L. Accordingly, the center axis of the shake correction optical system 16 is at a position closer to the soft limit P _L -P _L than the switching positions P _S and −P _S shown in FIG. 3, or from the switching positions P _S and −P _S. Judge whether it is in a position close to the origin.

In step S001 of FIG. 2, the absolute value of the correction optical system position Lr | Lr | is, if it is determined to be smaller than 0.8 times the soft limit _{P L,} the processing shown in step S006. In step S006, a magnification (gain) Pvias to be multiplied by the target speed VC1 when calculating the correction speed Vc is determined to be 1.0.

Furthermore, in step S007, the correction speed VC is calculated using the gain Pvias determined in step S006, and is output to the integration calculation unit 46 shown in FIG. As shown in FIG. 2, when the absolute value | Lr | of the correction optical system position Lr is 0.8 P _L or less (step S001), the gain Pvias is set to 1.0 (step S006). The correction speed VC calculated in step S007 is equal to the target speed VC1. As described above, when the central axis of the shake correction optical system 16 is located closer to the origin than the switching positions P _S and -P _S shown in FIG. 3, the correction output from the position bias control unit 44 shown in FIG. The speed VC is equal to the target speed VC1.

In contrast, in step S001 shown in FIG. 2, the absolute value of the correction optical system position Lr | Lr | if has been determined to be larger than 0.8 times the soft limit _{P L} is the step S002~ step S004 Make a series of decisions as shown. In steps S002 to S004, the direction of the target speed VC1 representing the moving direction of the shake correction optical system 16 (see FIG. 1) is a direction approaching the soft limits P _L and −P _L shown in FIG. It is determined whether the direction is away from P _L and −P _L.

In step S002 in FIG. 2, the correction optical system position Lr is either a positive direction of the soft limit P _L side from the positive direction of the switching position P _S shown in FIG. 3, the negative direction of the negative direction of the switching position -P _S to determine whether the soft limit -P _L side. In the present embodiment, by correcting the optical system position Lr is determined greater than zero or not, correction optical system position Lr is, two soft limit P _L, of the -P _L, either soft limit P _L, to determine whether you are close to the -P _L. After step S002, in step S003 or step S004, it is determined whether the direction of the target speed VC1 is positive or negative.

If it is determined in step S002 in FIG. 2 that the correction optical system position Lr is positive, and it is determined in step S003 that VC is positive, the gain Pvias is determined to be 0.2 (step S005). In this case, correction optical system position Lr is the positive direction of the soft limit P _L side from the positive direction of the switching position P _S shown in FIG. 3, and the direction of the target speed VC1 is from the origin positive software limit P _This is the direction approaching _L.

The gain Pvias is also determined to be 0.2 when the correction optical system position Lr is determined to be negative in step S002 of FIG. 2 and the correction speed VC is determined to be negative in step S004. (Step S005). In this case, correction optical system position Lr is the negative direction of the soft limit -P _L side from the negative direction of the switching position -P _S shown in FIG. 3, and the direction of the target speed VC1 is from the origin negative soft it is a direction approaching to the limit -P _L.

When the gain Pvias is determined to be 0.2 in step S005, the correction speed VC calculated in step S007 is 0.2 times the target speed VC1. That is, the center axis of the shake correction optical system 16 is located closer to the soft limits P _L and −P _L than the switching positions P _S and −P _S shown in FIG. 3, and the direction of the target speed VC1 is the soft limit. When the direction approaches P _L , −P _L , the magnitude of the correction speed VC is 0.2 times the target speed VC1.

On the other hand, when it is determined that the correction optical system position Lr is positive in step S002 of FIG. 2 and VC is determined to be negative in step S003, the gain Pvias is determined to be 1.0. (Step S006). In this case, correction optical system position Lr is the positive direction of the soft limit P _L side from the positive direction of the switching position P _S shown in FIG. 3, and the direction of the target speed VC1 is from the positive direction of the soft limit P _L It is a direction to go away.

Further, when it is determined that the correction optical system position Lr is negative in step S002 of FIG. 2 and VC is determined to be positive in step S004, the gain Pvias is determined to be 1.0 (step S002). S005). In this case, correction optical system position Lr is the negative direction of the soft limit -P _L side from the negative direction of the switching position -P _S shown in FIG. 3, and the direction of the target speed VC1 is negative software limit - it is a direction away from the P _L.

When the gain Pvias is determined to be 1.0 in step S006, the correction speed VC calculated in step S007 is 1.0 times the target speed VC1. That is, the center axis of the shake correction optical system 16 is located closer to the soft limits P _L and −P _L than the switching positions P _S and −P _S shown in FIG. 3, and the direction of the target speed VC1 is the soft limit. P _L, when a direction away from the -P _L, the magnitude of the correction speed VC is equal to the target speed VC1.

Thus, the position bias controller 44 changes the input target speed VC1 to the correction speed Vc based on the correction optical system position Lr. At this time, the direction of the target speed VC1 is soft limit _P L, and when a direction approaching the -P _L, soft limit _P L, and the case is a direction away from the -P _L, when calculating the modified velocity Vc The gain Pvias applied to the target speed VC1 is different.

Also, proximity correction optical system position Lr is, the switching position _P S shown in FIG. 3, -P _S from soft limit _P L, or a position close to the -P _L, the switching position _P S, the origin from -P _S The gain Pvias to be applied to the target speed VC1 differs depending on whether the position is in the position to be operated.

Here, in the present embodiment, the distance from the origin to the switching positions P _S , −P _S is set to 0.8 times the distance from the origin to the soft limits P _L , −P _L. The switching positions P _S and -P _S in the embodiment are not limited to this. The distance from the switching position P _S , −P _S to the soft limit P _L is determined from the viewpoint of securing the deceleration region of the shake correction optical system 16. However, in order to more effectively cancel out the shake of the photographing optical system, it is preferable to reduce the distance.

In this embodiment, the gain Pvias is set to 1.0 or 0.2. However, the gain Pvias used in this embodiment is not limited to this. The gain Pvias can take any value appropriate to prevent the shake correction optical system 16 from moving beyond the soft limits P _L and −P _L to a mechanical limit in a direction further away from the center position. For example, the gain Pvias may be changed transitively as the soft limits P _L and -P _L are approached.

  Here, the mechanical limit is a movement limit position on a dimension that is limited when the shake correction optical system 16 or the correction optical system holding frame 18 comes into contact with other peripheral components.

However, the amount of change from the target speed VC1 to the correction speed VC caused by the gain Pvias is such that the correction optical system position Lr is the soft limit when the correction optical system position Lr is closer to the soft limits P _L and −P _L. It is preferable that it is larger than the direction away from P _L and -P _L.

This is because when the correction optical system position Lr is in a direction approaching the soft limits P _L and −P _L , the shake correction optical system 16 is prevented from moving beyond the soft limits P _L and −P _L. It is necessary to suppress the speed of the correction optical system 16. On the other hand, when the correction optical system position Lr is away from the soft limits P _L and -P _L , the speed of the shake correction optical system 16 does not need to be suppressed, and it is more effective to approach the target speed VC1. This is because it is preferable from the viewpoint of correct shake correction.

  In the flowchart shown in FIG. 2, the movement of the shake correction optical system 16 has been described using one-dimensional coordinates. However, the shake correction optical system 16 according to the present embodiment moves in an arbitrary direction perpendicular to the optical axis L. Therefore, the processing of the flowchart is applied by extending it to two dimensions. At this time, one-dimensional coordinates orthogonal to each other may be controlled independently, or may be controlled using two-dimensional orthogonal coordinates. When using two-dimensional orthogonal coordinates, for example, the gain Pvias may be changed according to the size of the angle formed by the target velocity VC1 vector and the correction optical system position Lr vector.

  The integral calculation unit 46 shown in FIG. 1 calculates the correction lens target position Lc based on the correction speed VC from the position bias control unit 44. FIG. 4 is a block diagram showing a series of processes in the integral calculation unit 46 shown in FIG. The multiplier 76 multiplies the input correction speed VC and the sampling time st to calculate a new integrated value. The adding unit 78 adds the new integrated value from the multiplying unit 76 and the fed back output value of the integration calculating unit 46 before one sampling to calculate the corrected lens target position Lc.

Here, the limit processing is performed on the output value of the integration calculation unit 46 one sampling before delayed by the addition unit 78 so that the correction lens target position Lc does not exceed the soft limits P _L and −P _L shown in FIG. Has been made. That is, the output value extracted from the extraction unit 80 is converted into an output value before one sampling in the delay conversion unit 82 and then subjected to limit processing in the limit unit 84 before being added to a new integrated value. Note that Za in the delay conversion unit 82 represents the transfer function of the integration calculation unit 46 in the form of Z conversion.

  The limit unit 84 converts the input value from the delay conversion unit 82 so that the correction lens target position calculated by the addition unit 78 does not exceed the soft limit. For example, when the input value from the delay conversion unit 82 exceeds a predetermined upper and lower limit value, the input value is converted into a predetermined upper limit value or lower limit value. As described above, in the integral calculation unit 46 according to this embodiment, the limit unit 84 performs the limit process, thereby preventing the correction optical system 16 in FIG. 1 from coming into contact with the mechanical limit that is a physical limit. .

Further, since the limit processing of the integral calculation unit 46 is performed on the output value before one sampling before a new integral value is added, as shown in FIG. 5, the correction lens target position Lc is soft. time you are stuck to the limit P _L is short. In FIG. 5, the correction lens target position Lc calculated by the integration calculation unit 46 according to the present embodiment is indicated by a solid line, and the lens position (virtual lens position) Ld of the shake correction optical system 16 when the limit process is not performed. Is represented by a broken line.

According to the integral calculation unit 46 according to the present embodiment, even when the correction lens target position Lc is temporarily stuck in the positive direction of the soft limit P _L, the direction of correction velocity VC to be input, switched toward the origin At time t1, the shake correction operation is resumed. In contrast, if after the lead portion 80 of FIG. 4, as provided limit unit 84 is, for example, to t2 shown in FIG. 5, the lens position is stick to the soft limit P _L. Therefore, according to the integral calculation unit 46 according to the present embodiment, the correction lens target position Lc sticks to the soft limit, and the time during which the shake correction process does not work effectively can be reduced.

  In addition, according to the integral calculation unit 46 according to the present embodiment, the speed of the shake correction optical system 16 when the shake correction operation is resumed is compared with the case where the limit unit 84 is provided after the drawing unit 80. Can be suppressed. Therefore, a rapid speed change of the shake correction optical system 16 can be suppressed, and an impact or driving sound generated in the camera can be suppressed.

  The controller 48 shown in FIG. 1 calculates the amount of movement of the shake correction optical system 16 based on the correction lens target position Lc output from the integration calculation unit 46 and the correction optical system position Lr. FIG. 5 is a block diagram showing processing in the controller 48 shown in FIG. The controller 48 receives the correction lens target position Lc and the correction optical system position Lr, and performs PID control on driving of the shake correction optical system 16 shown in FIG.

  The subtraction unit 62 shown in FIG. 6 calculates the difference between the correction lens target position Lc and the correction optical system position Lr. The proportional term integrating unit 64 multiplies the proportional constant P by the difference calculated by the subtracting unit 62 to calculate a proportional element in PID control. The difference calculated by the subtractor 62 and the integral constant I are multiplied by the integral term multiplier 66 and then sent to the integrator 70. In the integration unit 70, an integration element in PID control is calculated. Further, the difference calculated by the subtraction unit 62 and the integral constant I are multiplied by the differential term multiplication unit 68 and then sent to the differentiation unit 72. In the differentiating unit 72, a differential element in PID control is calculated. Zb in the integrating unit 70 and the differentiating unit 72 represents the transfer function of the controller 48 in the form of Z conversion.

  In the adding unit 74 of the controller 48, the proportional element, the integral element, and the differential element are added, and the drive amount of the shake correction optical system 16 shown in FIG. 1 is calculated. As shown in FIG. 1, the drive amount calculated by the controller 48 is input to the PWM driver 50 as a drive signal. The PWM driver 50 drives the shake correction drive unit 24 according to the input drive signal, and moves the shake correction optical system 16 in a direction perpendicular to the optical axis L.

  FIG. 7 is a graph showing the correction lens target position Lc and the like output when the camera shown in FIG. 1 is shaken to perform shake correction processing. FIG. 7A shows the time change of the correction lens target position Lc and the correction optical system position Lr, and FIG. 7B shows the time change of the drive amount output from the controller 48. Has been. The horizontal axis (time) of the graph (a) and the horizontal axis (time) of the graph (b) correspond to each other.

The correction optical system position Lr is initially stuck in the vicinity of the negative soft limit −P _L , but starts to move toward the origin at time t3, and at the time t1 the negative switching position −P. Pass _S.

When the processing of the position bias controller 44 at time t3 to t4 is confirmed in FIG. 2, the processing is performed in the order of step S001 → step S002 → step S004 → step S006, and the gain Pvias is set to 1.0. That is, in the time t3~t4 shown in FIG. 7 (a), since the correction optical system position Lr is moving away from the soft limit -P _L, the gain Pvias is 1.0. Therefore, the amount of change in speed from the target speed VC1 to the correction speed VC is 0%. At time t3 to t4, the shake correction optical system 16, even though the correction optical system position Lr is a soft limit -P _L vicinity, because it is controlled so as to approach the target speed VC1, the image blur effectively Can be countered.

Further, at time t4 to t5, the position bias control unit 44 shown in FIG. 2 performs the processing from step S001 to step S006, so that the gain Pvias is determined to be 1.0 as at time t3 to t4. That is, at time t4 to t5, the correction for the correction optical system position Lr is located at the origin side than the switching position -P _S (the center side of the movement range), the gain Pvias becomes 1.0 from the target speed VC1 rate The amount of change to VC is 0%. Therefore, before and after the time t4 to pass through the switching position -P _S, the gain Pvias does not change from 1.0, rapid change of the drive amount and drive speed of the shake correction optical system 16 is suppressed.

At time t5 in FIG. 7 (a), the correction optical system position Lr passes through the positive direction of the switching position _{P S.} At time t5 to t7, the position bias control unit 44 shown in FIG. 2 performs the process from step S001 → step S002 → step S003 → step S005, and therefore the gain Pvias is determined to be 0.2.

That is, in the time t5~t7 shown in FIG. 7, since the correction optical system position Lr is moving toward the soft limit _{P L,} the gain Pvias is 0.2. Therefore, the speed change amount from the target speed VC1 to the correction speed VC of the shake correction optical system 16 is 80%, and the moving speed of the shake correction optical system 16 is suppressed. Accordingly, as shown in FIG. 7 (a), even if the correction optical system position Lr is overshoots the correcting lens target position Lc, is sufficiently decelerated by the soft limit P _L vicinity, blur correction optical system 16 Is prevented from reaching the mechanical limit.

However, before and after the time t5 to pass through the switching position _{P S,} the gain Pvias changes from 1.0 to 0.2. For this reason, as shown in FIG. 7B, at time t6, which is immediately after time t5, a sudden change in the drive amount of the shake correction optical system 16 and a sudden change in the moving speed may occur. is there.

As shown in FIG. 7A, the correction optical system position Lr remains in the vicinity of the soft limit in the positive direction for a while after time t7, but starts moving again toward the origin at time t8, and at time t9. passing the positive direction of the switching position P _S. At time t8 to t9, because the correction optical system position Lr is moving away from the soft limit _{P L,} the gain Pvias becomes 1.0, the amount of change from the target speed VC1 to compensation velocity VC is 0% (See FIG. 2).

At time t8 to t9, the shake correction optical system 16, since the correction optical system position Lr is controlled so as to approach the target speed VC1 even soft limit P _L vicinity, it is possible to cancel an image shake effectively . In addition, since the gain Pvias remains 1.0 before and after the time t9 passing through the switching position Ps, rapid fluctuations in the drive amount and drive speed of the shake correction optical system 16 are suppressed.

At time t10 in FIG. 7A, the correction optical system position Lr passes the negative switching position -Ps. At time t10 to t12, because the correction optical system position Lr is moving toward the soft limit -P _L, the gain Pvias is 0.2. Therefore, the amount of change in speed from the target speed VC1 to the correction speed VC is 80%, and the movement speed of the shake correction optical system 16 is suppressed. Therefore, as shown in FIG. 7 (a), even if the correction optical system position Lr is overshoots the correcting lens target position Lc, and sufficiently decelerated in soft limit -P _L vicinity, blur correction optical system 16 is Reaching the mechanical limit is prevented.

  However, the gain Pvias changes from 1.0 to 0.2 before and after the time t10 passing through the switching position -Ps. For this reason, as shown in FIG. 7B, at time t11 that is immediately after time t10, there is a case where a sudden change in the driving amount of the shake correction optical system 16 or a sudden change in the moving speed associated therewith occurs. is there.

Thus, in the shake correcting device according to the present embodiment, the moving direction of the blur correction optical system 16, a soft limit P _L, and when a direction approaching the -P _L, soft limit P _L, away from the -P _L The amount of change in the moving speed of the shake correction optical system 16 is changed depending on the direction.

  That is, when the movement direction of the shake correction optical system 16 is a direction approaching the soft limit, the position bias control unit 44 suppresses the movement speed of the shake correction optical system 16 (change amount 80%). The optical system 16 is prevented from reaching the mechanical limit. On the other hand, the position bias control unit 44 does not suppress the speed of the shake correction optical system 16 when the movement direction of the shake correction optical system 16 is away from the soft limit (change amount 0%). Therefore, since the lens CPU 30 controls the shake correction optical system 16 so as to approach the target speed VC1, it is possible to perform effective shake correction.

Further, the moving direction of the blur correction optical system 16, when a direction away from the soft limit P _L, -P _L, as compared with the case where the direction approaching software limit P _L, the -P _L, switching position - P _S, is small the amount of change in the speed of the correction optical system 16 deflection before and after _{P S.} Therefore, in the shake correction apparatus according to the present embodiment, when the movement direction of the shake correction optical system 16 is a direction away from the soft limits P _L and −P _L , an impact due to a sudden speed change of the shake correction optical system 16 is achieved. Or generation | occurrence | production of a drive sound is suppressed. Therefore, the frequency of occurrence of impact or driving sound due to a rapid speed change of the shake correction optical system 16 is suppressed.
Comparative example

  FIG. 8 is a flowchart showing a series of processes performed by the position bias control unit of the shake correction apparatus according to the comparative example of the present invention. The camera on which the shake correction apparatus according to the comparative example is mounted is the same as the camera (FIG. 1) described in the embodiment except for the processing of the position bias control unit shown in FIG.

Between each soft limit P _L , -P _L and the origin, the switching position P is located at a position where the distance from the origin is 0.8 times the distance from the origin to each soft limit P _L , -P _{L. S} and -P _S are provided.

  In step S201 shown in FIG. 8, as in step S001 of FIG. 2, the shake correction optical system 16 is determined by determining whether or not the absolute value | Lr | of the correction optical system position Lr is smaller than a predetermined threshold value. Determine the position.

In step S201 of FIG. 8, the absolute value of the correction optical system position Lr | Lr | is, if it is determined to be smaller than 0.8 times the soft limit _{P L,} determines the gain Pvias to 1.0 (step S203 ). On the other hand, if it is determined in step S201 that the absolute value | Lr | of the correction optical system position Lr is larger than 0.8 times the soft limit P _L , the gain Pvias is determined to be 0.2 (step S201). S202).

That is, the position bias controller according to the comparative example, correction optical system position Lr is, the switching position _P S shown in FIG. 3, or closer -P _S soft limit _P L -P _L, the switching position _P S, - only by determination of whether proximity to the origin than P _S, determines the gain Pvias.

  9 includes the position bias control unit that performs the series of processes shown in FIG. 8 in the camera shown in FIG. 1 instead of the position bias control unit 44, and shake correction processing by shaking the camera greatly in the same manner as in FIG. This is the output result when

  When the processing of the position bias control unit 44 at time t13 to t14 is confirmed in FIG. 8, the processing is performed in the order of step S201 → step S202, and the gain Pvias is set to 0.2. That is, at time t13 to t14 shown in FIG. 7A, the amount of change in speed from the target speed VC1 to the correction speed VC is 80%. Therefore, the shake correction optical system 16 is controlled so as to approach a speed 20% of the target speed VC1, and thus cannot sufficiently cancel the image blur.

Further, at time t14 to t15, as shown in FIG. 8, the position bias control unit performs the processing from step S201 to step S203, and therefore the gain Pvias is determined to be 1.0. That is, at time t14 to t15, the correction for the correction optical system position Lr is located at the origin side than the switching position -P _S (the center side of the movement range), the gain Pvias becomes 1.0 from the target speed VC1 rate The amount of change to VC is 0%. Therefore, the gain Pvias changes from 0.2 to 1.0 before and after the time t4 passing through the switching position -Ps. For this reason, as shown in FIG. 9B, when the drive amount of the shake correction optical system 16 is suddenly changed or the movement speed is suddenly changed at time t15 immediately after time t14. There is. Further, as shown in FIG. 9A, the difference between the correction optical system position Lr and the correction lens target position Lc may be temporarily increased around time t15 due to a sudden change in the driving amount. .

  The output result in the vicinity of time t16 is almost the same as the output result in the vicinity of time t5 in FIG. 7 described in the embodiment.

  At times t19 to t20, similarly to times t13 to t14, processing is performed in the order of step S201 → step S202, and the gain Pvias is set to 0.2. (See FIG. 8). On the other hand, from time t20 to t22, the process from step S201 to step S203 is performed, so that the gain Pvias is determined to be 1.0. Therefore, the gain Pvias changes from 0.2 to 1.0 before and after the time t20 passing through the switching position -Ps. For this reason, as shown in FIG. 9B, at time t21, which is immediately after time t20, a sudden change in the driving amount of the shake correction optical system 16 and a sudden change in the moving speed associated therewith occur. There is.

  The output result near time t22 is substantially the same as the output result near time t10 in FIG. 7 described in the embodiment.

As described above, in the shake correction apparatus according to the comparative example, when the shake correction optical system 16 passes through the switching positions −P _S and P _S , regardless of the moving direction of the shake correction optical system 16, the switching position −P _S , gain Pvias fluctuates P _S before and after. Therefore, compared with the embodiment shown in FIG. 7B, the comparative example shown in FIG. 9B has a higher frequency of rapid fluctuations in the drive amount. For this reason, the occurrence of impact or driving sound due to a rapid change in speed of the shake correction optical system 16 is greater than in the embodiment.

  Further, even if the movement direction of the shake correction optical system 16 is a direction away from the soft limit, in order to suppress the speed of the shake correction optical system 16 (change amount 80%), the shake is more effective as the embodiment. Correction cannot be performed.

FIG. 1 is a block diagram illustrating shake correction control in a camera equipped with a shake correction apparatus according to an embodiment of the present invention. FIG. 2 is a flowchart showing a series of processes performed by the position bias controller shown in FIG. FIG. 3 is a schematic diagram showing a control movement limit position and a switching position in the shake correction optical system shown in FIG. FIG. 4 is a block diagram showing processing in the integral calculation unit shown in FIG. FIG. 5 is a graph showing the time change of the output in the integral calculation unit shown in FIG. FIG. 6 is a flowchart showing a control flow of the position bias control unit in the shake correction apparatus according to the comparative example. FIG. 7 is a graph showing the result of shake correction processing by the camera shown in FIG. FIG. 8 is a flowchart showing a control flow of the position bias controller in the shake correction apparatus according to the comparative example. FIG. 9 is a graph showing temporal changes in position and drive amount of the shake correction optical system in the shake correction correction apparatus according to the comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Camera body part 4 ... Lens barrel 16 ... Shake correction optical system 18 ... Correction optical system holding frame 24 ... Shake correction drive part 26 ... Correction optical system position detection part 28 ... Angular velocity sensor 30 ... Lens CPU
42 ... Lens target speed conversion unit 44 ... Position bias control unit 46 ... Integration calculation unit 48 ... Controller 50 ... PWM driver

Claims (9)

Moving means for moving an optical component provided on the optical axis of the optical system in a direction crossing the optical axis;
A speed control unit that changes a moving speed of the optical component by the moving unit according to a position and a moving direction of the optical component;
The speed control unit moves the optical component in a direction in which the movement direction of the optical component is a direction approaching the movement limit position on the control and in a direction away from the movement limit position on the control. A shake correction apparatus characterized by changing the amount of change in the vibration. The shake correction apparatus according to claim 1,
The shake control apparatus, wherein the speed control unit suppresses the moving speed of the optical component based on the amount of change when the moving direction of the optical component is a direction approaching the movement limit position on the control. . The shake correction apparatus according to claim 1 or 2,
The amount of change when the movement direction of the optical component is a direction away from the control movement limit position is the change amount when the movement direction of the optical component is a direction approaching the control movement limit position. A shake correction apparatus characterized by being smaller than a change amount. The shake correction apparatus according to any one of claims 1 to 3, wherein
In the case where the moving direction of the optical component is a direction away from the center position of the moving range of the optical component, and the case where the moving direction of the optical component is a direction approaching the center position of the moving range of the optical component, A shake correction apparatus characterized by changing a change amount of a moving speed of an optical component. The shake correction apparatus according to any one of claims 1 to 4, wherein
There is a switching position between the center position of the movement range of the optical component and the movement limit position on the control,
In the case where the position of the optical component is at a position closer to the control limit position than the switching position and the position where the position of the optical component is closer to the center position than the switching position, A shake correction apparatus characterized in that the change amount of the moving speed of the optical component can be changed. The shake correction apparatus according to any one of claims 1 to 5, wherein
There is a movement limit position on the dimension where the optical component comes into contact with another component in a direction further away from the control movement limit position with respect to the center position of the movement range of the optical component. Shake correction device. The shake correction apparatus according to any one of claims 1 to 6, wherein
The speed control unit calculates the moving speed of the optical component necessary for canceling the shake of the optical system, and changes the calculated moving speed according to the position and moving direction of the optical component. A shake correction device characterized by the above.   A lens barrel comprising the shake correction device according to claim 1.   A camera comprising the shake correction apparatus according to claim 1.

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